Flexible walled containers



Oct. 161956 J D. THOMPSON FLEXIBLE WALLED CONTAINERS Filed April 18, 1952 MM W 1 Ts N mp 5 WW w n 1 m A United States Patent Ofifice 2,766,926 Patented Oct. 16, 1955 FLEXIBLE WALLED CONTAINERS Jay D. Thompson, Minneapolis, Minn, assignor to Bernie Bro. Bag Company, Minneapolis, Minn., a corporation of lVIissouri Application April 18, 1952, Serial No. 283,101

4 Claims. (Cl. 229-55) This invention relates to improvements in the construction of containers made of paper, light cardboard, cloth and other flexible materials that are used for the packaging and display of bulk material, such as flour, cereal, sugar, soap powders and other like commodities.

This application is a continuation-in-part of my copending application Serial No. 266,122 filed January 12, 1952.

The present invention relates to improvements in foldable merchandise containers, which are made and shipped in a flat condition and are then filled and closed at the plant, factory or mill producing the commodity to be sold. The containers, more usually called bags, are of rectangular parallelepipedon shape and have a pair of major walls (front and back), a pair of minor walls (sides), a bottom and a top closure. Such containers or bags are economical to make .and use since they can be shipped and stored in a small space. They may be constructed in accordance with the flat-fold or intucked principle. The bags are shipped in collapsed (fiat-folded or in-tucked) condition from the bag manufacturer to the commodity producer or packager, and he stores these bags in collapsed form until they are needed. At that time the commodity producer or packager will set up (open) the containers, fill them with merchandise, close them and ship them on for ultimate sale to the consumer.

Bags of this type are used for bulk granular solids such as sugar, salt, rice, barley, breakfast foods, etc. These commodities, by their nature flow in a manner much like a liquid. When a bag of this commonly accepted type is filled the bulk granular solid exerts an internal pressure which causes the containers to become somewhat rounded at the corners and edges. This is undesirable because it uses more space for transporting in boxes and more especially because of the poor display features of such containers when placed on the merchants shelf for ultimate display and sale to the consumer. Thus, a somewhat rounded-off bag does not present neat, wide, flat front and back surfaces for the display of trademarks, manufacturers name, etc.

It is desirable for economy to use containers which fold fiat before filling, but for merchandising purposes the container should retain substantially the form of a rectangular parallelepipedon after filling, so as to present flat or nearly fiat walls, as well as neat edges and corners. However, this objective has not been possible to attain in practice.

In the design of bags the reater the difference between the width of the front (and back) as compared with the width (front-to back dimension) of the sides in the theoretical bag shape, the more pronounced will be the bulging and rounding effects due to the aforesaid pressure when the bag is filled. Stated another Way, a very flat theoretical bag shape will exhibit a greater tendency of the fiat front and back walls to bulge and the edges and corners to round, than one in which the front (and back) panels are the same or nearly the same width as the sides. Therefore, the foldable bag designer has had to keep the sidewalls nearly as wide as the front and back walls, especially for very flowable materials, such as coffee, rice and beans. Accordingly, there have been practical limits beyond which the bag designer could not usually go and as a result the front and back walls of usual flexible walled bag designs have usually had to have a side-to-side width which does not much exceed 1 /2 to 2 times the front-to-back (width) dimension of the side walls and even then the aforesaid bulging and rounding has had to be tolerated as a problem heretofore incapable of economical solution.

From the merchandising standpoint in competitive markets it is desirable to have as much space as possible on the front and back of the bag so as to allow prominent display of trademarks, etc., but provision of such space has been rendered impossible in packaged goods except by the use of rigid boxes made of strong paperboard having inherent stilfnesses suflicient to withstand the aforesaid distorting pressure of the commodity within the package or for very low density commodities such as cornfiakes. However, use of such rigid packages is limited, since when empty they cannot be shipped economically after being set up because of the large space they occupy, and hence are usually fabricated by uarge and expensive machinery at the place where they are to be filled with the commodity. In addition, the cost of rigid card board generally exceeds the cost of paper. Smaller mills cannot afford machinery to make boxes at the place of filling.

It is an object of the present invention to overcome the aforesaid disadvantages of the prior art and to provide an improved flexible walled container, which is economical to make and ship, capable of being folded flat when empty, constructed so as to resist bulging and rounding, and resembles a box in appearance when it is filled and closed.

It is a further object of this invention to provide an improved flexible walled container capable of being folded flat for storage and yet capable of being set up into a relatively fiat rectangular package presenting flat walls with neat appearing edges and corners.

It is a further object of the invention to provide an improved bag structure having reinforcement capable of maintaining selected walls of the filled bag in flat neat condition.

it is a further object of the invention to provide an improved bag structure capable of being set up and filled to provide a package of substantially rectangular parallelepipedon configuration wherein the front and back walls are relatively much greater in width as compared to the side walls, than has heretofore been possible in such bag structures.

It is a further object of the invention to provide a flexible walled bag structure of parallelepipedon shape wherein reinforcements are provided throughout substantially the entire extent of the front, back and side walls of the bag when it is filled and closed.

It is another object of the invention to provide flexible walled bags having stiffening panels designed to reinforce the entire surface of the major and minor walls of a bag.

It is a further object of the invention to provide an improved in-tuck bag structure including a stiffening liner so folded that it will operate on the principle of a toggle to stretch and hold the flexible bag Wall until it takes the form of a rectangular parallelepipedon when it is opened for filling and when closed and used.

It is a further object of the invention to provide a foldable stiffening panel for foldable intuck flexible walled in open position after opening and to reinforce and maintain its shape and particularly the edges and corners thereof. r r r Qther and further objects of the invention are those inherent and apparent the apparatus herein illustrated, described and claimed.

The invention is illustrated with reference to the drawings in which corresponding numerals refer to the same parts and in which 7 a Figure 1 is a front elevational view partially broken away showing; flexible 'walled container of the intucked type, with the bag and stiffening panel therein in partially folded position; 7

FigureLZ isa vertical sectional view taken along the lines Zeal-of Figure 1 plane of lines -66 of Figure 5.;

Figure 7 is a fragmentary horizontal sectional view partially broken away of a modified form of the invention utilizing a multi-ply bag body with the stiffening panel structure mounted between the plies.

In accordance with the invention'herein disclosed in Figures 1 -6 there is shown a flexible walled bag body having substantially the form of a rectangular parallelepipedon with a stiffening panel mounted therein for reinforcement .of. the major and minor walls of the bag body. In Figure 7 there is shown a flexible walled bag made of a plurality of plies wherein the stilfening panel is mounted between the plies.

According'to this illustrative embodiment of the invention, a stifiening sleeve is provided, this being of cardboard, paperboard, pulpboard, stifl plastic sheet or the like. The sleeve has the same'height as the bag when'closed, and the sleeve has a rectangular cross section such that it slightly stretches the bag wall when opened. 7 a

In the illustrated embodiment of the invention shown in Figures l-6, there is shown an in-tuck flexible bag generally designated 10 of usual form, having a front '11, a back 12, sides :13 and 14, a bottom. 15 and top closure portions 16 and 17 adapted to be folded one over the other to form a top for the bag when it is filled and closed. The bag 10 is in every respect of usual flexible sheet construct-ion; it is formed from a flat sheet the left edge 23 to the right edge 24. The back 12 has the'sarne size and shape; The sides 13 and 14 are likewise rectangular and are creased (folded) in at their centerl'ines CL, when the intuck form is used.

bags, the panel acting, during use to maintain the bag.

with the corresponding bag walls as shown in'Figure' 5,

forcing and stabilizing makes a much 'neater'and more useful package than would be otherwise possible.

In the illustrated form of the invention the bag body 19 is of the infold (or in-tuc') type, with the sides 13 and 14 folded in at their respective verticaLcenterlines 43 and 44. Similarly, the bottom 15 is folded up along itsxcenter l-ine'42. The stiffening insert=26 is notched along the lines 4t)41 at each side so as to V accommodate the. bottom 15 when it is folded up as 7 shown in Figures 1 and 3.

The sleeve 26 is constructed .so that its periphery slightly exceeds the inner periphery of the bag-body and its sides 29 and '30rare creased so as to infold in conformance with the'si'des 13 and 14, 'respectively, .of the bag. The-two halves 29a and 29b of side 29 (of the stiff insert) thus fold in along line 43a and the two halves whole bag (and the stiff insert) is folded in '(asin Figures Withinthe bag body 10 is placed the stiffening insert generally designated 26. The insert 26 is essentially in the form of'a sleeve and has a front face 27, a back face 2'3 and side faces 23 and .30. The stiffening insert 26 may be considered as a'tube of rectangular cross section, open on both ends. Its face portions are substantially geometrically commensurate with the corresponding wall :ofthe ;bag-:body L9. 7

In service the faces of the stifiening insert 26 register 75 plastic sheet or the like.

.l and 3) the toggle side 29a29b and the toggle side Talia-36b :will exert no tension to stretch the periphery of the bag tube, but as the bag is opened from the Figure 1 position, a certain position, as indicated by the dottedlines of Figure 6, is reached at which the toggling action begins to take up the'slack in the, bag periphery composed of left side 13, back 12, right side 14' and front 11. Then as additional pressureis .exerted 'on the side 29 (composed of halves 29a and 295) and on the side 30 (composed of halves 30a and 30b) the final straightening of halves 29a and 2% into line and the final straightening of lines 30a and 30b intoline produces a toggling action which imposes a condition of neat tautness in the entire bag body ill, at least in a peripheral direction. This pulls the bag body neatly around'cornel's 34, 35, 36 and 37, and as the halves 29a and 29b and the halves 39a and 30b go slightly over-center the bag.

is snapped into open position. Often the pressure of the bulk solid material is relied upon to exert the needed final opening and holding force in the direction of arrows 52 and 53. It is not desirable that the tubular insert 26 exert undue force but simply enough to straighten out wrinkles in the bag and give it a neat appearance.

The insert 26 may be secured to the bag body 10 by any suitable means, for example adhesives. It is helpful that precautions be taken to prevent material from finding its way. between the insert 26 and bag body 10 since material in such location causes unsightly bulges on the surface of the unit. Therefore, it is desirable to use a continuous adhesive fastening between the inside of the bag front 11 and at least the upper and lower edges of the reinforcing sleeve. This adhesive should preferably remain sufli ciently plastic so as to allow a slight but desirable creepage of the side 13 of the bag relative to side 29 of the stiffener and a similar creepage between side 14 of the bag and side 30 of the stifiener. Adhesives, such as latex or permanently plastic non-drying adhesives are desirable for this purpose because they permit the desired slight being composed :of slick paper, moisture imperviouspaper,

The two halves 29a and 29b act as a Throughout the illustrations herein, because of limitations of draftmanship, it has been necessary to exaggerate the thickness of the material of the bag proper as compared With the thickness of the stiffener insert. In actual practice the bag or plies 61 and 62 are made of suitable bag paper, foil, cloth, plastic, etc. of one or more plies and of customary strength and thickness for the service intended. Thus, for example, a 3-pound sugar or rice bag may be made of paper .003 inch to .009 inch thick in one or several plies, the lesser dimension being for single ply and the greater dimension being (usually) for multiple plies. Other sizes of bags for other services require flexible papers of different weights .and grades. The stiffening insert is usually of stiff paperboard, boxboard, such as pulpboard .025 inch to .100 inch thick or even thicker. It is therefore proper to consider the flexible bag proper as being of thin flexible and tough sheet material, whereas the reinforcing insert is relatively much thicker and far less flexible than the bag material.

As many apparently widely different embodiments of this invention may be made Without departing from the spirit and scope thereof, it is to be understood that I do not limit myself to the specific embodiments disclosed herein.

What I claim is:

1. A tubular bag of flexible material adapted to be infolded to the flat condition, said bag having a front and a back, a pair of sides, bottom and top closure portions of the front, back and sides adapted to be folded over each other to form a top when the bag is filled and closed, said bag when closed forming a theoretical container space shaped substantially as a rectangular parallelepipedon, a stiff reinforcement within said bag, said reinforcement being of a material substantially thicker and stiffer than the flexible material of which the bag is composed, said reinforcement also being in the form of a tube of substantially the same horizontal rectangular cross-sectional shape as that of the bag, and having a front face, a back face and a pair of side faces, said faces registering with and being substantially geometrically commensurate with the inner surfaces of the corresponding walls of the bag when said insert is within the bag body, the horizontal cross-sectional peripheral dimension of said tubular insert being very slightly in excess of the corresponding peripheral dimension of the inside of the bag body when said insert and bag body are opened to the filling condition, each of the side faces of said insert being creased along a vertical center line extending from the bottom to the top and foldable inwardly with the bag body when the bag is collapsed to flat condition, the bottom of the bag being creased along a transverse center line extending from one side to the other side of the bag and foldable upwardly when the bag is collapsed to flat condition, each side face of the insert being notched to accommodate said upward fold of the bottom.

2. The bag structure set forth in claim 1 further characterized in that said insert is adhesively secured to the inside of the bag body.

3. A tubular bag of flexible material adapted to be infolded to flat condition, said bag having a front and a back, a pair of sides, bottom and top closure portions on the front, back and sides adapted to be folded over each other to form a top when the bag is filled and closed, said bag when closed forming a container space shaped substantially as a rectangular parallelepipedon, a stiff reinforcement insert within said bag, said reinforcement insert being made of a material substantially thicker and stiffer than the flexible material of which the bag is composed, said reinforcement insert also being in the form of a tube of substantially the same horizontal rectangular cross-sectional shape as that of the bag, and having a front face, a back face and a pair of side faces, said faces registering with and being substantially geometrically commensurate with the inner surfaces of the corresponding walls of the bag when said insert is within the bag body, said reinforcement insert being secured to said bag body by means of an adhesive which is sufficiently plastic so as to allow the reinforcement insert to creep slightly with reference to the bag body when the bag is opened, each of the side faces of said reinforcement insert being creased along a vertical centerline extending from the bottom to the top and foldable inwardly with the bag body When the bag is collapsed in flat condition, the bottom of the bag being creased along a transverse centerline extending from one side to the other side of the bag and foldable upwardly when the bag is collapsed to flat condition, each side face of the insert being notched to accommodate said upward fold of the bag bottom.

4. The bag structure of claim 3 in which the horizontal cross-sectional peripheral dimension of said insert is slightly in excess of the corresponding peripheral dimension of the inside of the bag body when said insert and bag body are opened to the filling condition.

References Cited in the file of this patent UNITED STATES PATENTS 1,467,268 Deiss Sept. 4, 1923 1,907,172 Arzet May 2, 1933 2,400,716 Sattler May 21, 1946 2,556,321 Denton June 12, 1951 FOREIGN PATENTS 202,857 Great Britain Aug. 30, 1923 627,711 Great Britain Aug. 15, 1949 

